Historical background: Great Depression is in full swing. The Tory government is imploding due to Bennett's recent adoption of interventionist economic policy. Two new parties have formed: the socialist CCF and Social Credit.

What did the Liberals campaign on in 1935, anyway? Ending the interventionist program of the Conservatives, or expanding it?

They campaigned on middling economic reform. So they kept what the Tories started, expanded public works projects in conjunction with the provinces, and returned to free trade. King built a good chunk of our welfare state (family allowance, unemployment insurance, pensions, housing/mortgage assistance), but he did it in stages and cautiously.